The study aimed to determine the effect of acute, one-time physical effort performed under different environmental temperature conditions on erythrocyte deformability in healthy young men. This exploratory randomized parallel-group study involved 30 men randomly assigned to an experimental group exercising at −10 °C in a climatic chamber and a control group exercising under thermoneutral outdoor conditions. Erythrocyte deformability was assessed using the elongation index (EI), reflecting erythrocyte elasticity and the ability to pass through microcirculation vessels. Participants performed an incremental 20 m shuttle run test. Venous blood samples were collected before and immediately after exercise, and erythrocyte deformability was analyzed using a Lorrca analyzer across a shear stress range of 0.30–60.00 Pa. A two-factor repeated-measures analysis of variance was applied. An increase in EI after exercise was observed in both groups, predominantly at higher shear stress values, indicating enhanced erythrocyte deformability under conditions of increased shear forces. However, the magnitude of post-exertion changes differed between groups. At lower shear stress levels (0.30 Pa and 0.58 Pa), EI tended to decrease after exercise. These findings indicate that a single bout of physical effort influences erythrocyte deformability, while the potential effects of cold exposure on this response remain uncertain and warrant further investigation.

The paper deals with an analysis of transverse vibrations of a bucket elevator chain, arising during the acceleration and braking process of the drive sprocket. A linear model of a moving string was used to describe the vibrations, and the force of gravity and the longitudinal force component resulting from the axial acceleration were taken into account. A vibration analysis was performed in a non-inertial coordinate system connected with the moving ends of the chain. Galerkin’s method was used in the numerical calculations. Example calculation results for the industrial bucket elevator made it possible to determine the conditions for exceeding the permissible level of transverse displacements in the chain. The created calculation algorithm can be used in engineering practice at the design stage of the bucket elevator system, allowing the optimal control method for the acceleration and deceleration process of the drive sprocket to be determined based on the given operating parameters.

Background: Exercise in the cold is an attractive option for many athletes. Erythrocyte aggregation, as one of the main rheological parameters, constitutes an important indicator of microcirculation and oxygen transport capacity in the human body. Acute exercise and environmental cold may alter erythrocyte aggregation. We compared immediate hematological, aggregation, metabolic, and hormonal responses to progressive shuttle run exercise in a cold chamber and outdoors. Methods: This exploratory parallel-group analysis included 30 young healthy male students allocated to exercise in a climatic chamber at −10 °C (n = 15) or outdoors at 18 °C (n = 15). Blood was collected before and immediately after exercise. Group × time interactions were assessed using repeated-measures ANOVA and within-group comparisons used Bonferroni adjustment. Results: Erythrocyte amplitude of aggregation (AMP) showed a significant group × time interaction (p = 0.0014). In the paired analysis, the between-group difference in AMP change was −3.24 au (pointwise 95% CI −5.12 to −1.36). Lactate showed a nominal interaction (p = 0.016). Within the experimental group, red blood cell count, hemoglobin, hematocrit, mean corpuscular volume, aggregation index (AI) and lactate increased, whereas AMP and aggregation half-time (T½) decreased (all p < 0.001). Estimated plasma-volume change did not differ significantly between settings. Conclusions: Exercise in the cold-chamber setting was associated with a greater reduction in the optical aggregation amplitude. Further studies are needed to clarify the contribution of temperature and the physiological significance of these changes.